Choosiness and Disgust: A Biocultural Study of Social Change

Disgust and Choosiness:A Biocultural Study of Social Change

Dr Geoff Kushnick School of Archaeology and Anthropology ANU College of Arts and Social Sciences

Fulbright Scholars Program

American Institute forIndonesian Studies

Impal Marriage Project Acknowledgments

Karo people who participated in the study

Dan FesslerAnthropology, UCLA

Fikarwin Zuska AnthropologyUniversity of North Sumatra

Karmila KaroLasma SinagaIkhsan Ginting

Fessler DMT, 2007. Neglected

natural experiments germane to

the Westermarck hypothesis: the

Karo Batak and the Oneida

community. Hum Nat, 18, 355-64.

Kushnick G, Fessler DMT, 2011.

Karo Batak cousin marriage,

cosocialization, and the

Westermarck hypothesis. Current

Anthropology, 52(3), 443-448.

Schematic Diagram of Matrilateral Cross-Cousin (impal) Marriage among the Karo Batak of North Sumatra, Indonesia

Kushnick G, Fessler DMT, 2010. Study of marriage and baptism records at Catholic

Parish, Kabanjahe, North Sumatra. Center for Culture, Brain, and Development, UCLA.

% of Total Marriages between Impal

• Edvard Westermarck• Finnish sociologist• 1862-1939• “The History of Human

Marriage” (1891)

“Natural Experiments” Showing Negative Imprinting

(aka Westermarck Effects)

Israeli kibbutzim

Taiwanese sim pua marriage

• Disgust evolved as a mechanism to avoid disease-causing agents

• Co-opted for two other functions related to:

• Mating

• Morality

Tybur JM, Lieberman D, Griskevicius V, 2009. Microbes, mating, and morality: Individual

differences in three functional domains of disgust. J Pers Soc Psychol, 97, 103-122.

Tybur JM, Lieberman D, Kurzban R, DeScioli P, 2013. Disgust: evolved function and

structure. Psychol Rev, 120, 65-84

Fessler DMT, Navarette CD,

2004. Third-party attitudes

toward sibling incest:

Evidence for Westermarck's

hypotheses. Evol Hum Behav,

25, 277-294.

Antfolk J, Karlsson M,

Bäckström A, Santtila P, 2012.

Disgust elicited by third-party

incest: the roles of biological

relatedness, co-residence, and

family relationship. Evol Hum

Behav, 33, 217-223.

Antfolk et al. (2012):Respondents cosocialized with cousins more disgusted by vignettes featuring incest; also more disgusted when incestuous couple in vignette cosocialized.

Fessler & Navarette (2004):Respondents cosocialized with cousins more disgusted by vignettes featuring incest.

Vignette experiment:

• 215 Karo men and women age 18 to 95 from 51 villages

• Each respondent interviewed briefly about coresidence history with impal

• Then, each presented with 4 vignettes featuring hypothetical Karo women and their impal

• In halfdescribed as having grown up in adjacent households since they were small

• In the other halfdescribed as growing up in a very far away village

• Asked how disgusting it would be if the woman and her impal married.

Hypothesis 1

Participants cosocialized with their impal should experience more disgust. For this

hypothesis, cosocialization was operationalized as number of years from birth to age 10 that the respondent lived in the same village as at least one of his or her impal.

Hypothesis 2

Participants should experience more disgust when presented with vignettes that feature a woman marrying an impal with whom she was cosocialized. For this hypothesis, cosocializaton was operationalized as growing

up in adjacent houses.

Hypothesis 3

There should be concomitant secular trend toward increasing disgust for impal marriage in male and female respondents.

Pro

po

rtio

n o

f R

esp

on

ses

Responses were Poisson Distributed

H3 There should be concomitant secular trends toward increasing disgust for impal marriage in male and female respondents.

Further study of already-collected data will investigate why male feelings toward impal marriage have changed but female feelings have remained constant.

Why are males more choosy?

- Patriarchal values?

- Male over-valuation of attractiveness of potential partners?